# Synchronizing billboard with entity position

**URL:** <https://community.cesium.com/t/synchronizing-billboard-with-entity-position/1577>\
**Category:** CesiumJS\
**Created:** [October 11, 2014, 4:20pm UTC](https://community.cesium.com/t/synchronizing-billboard-with-entity-position/1577 "2014-10-11T16:20:32Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Stefanie\_Schmidt](https://avatars.discourse-cdn.com/v4/letter/s/71e660/32.png) [@Stefanie\_Schmidt](https://community.cesium.com/u/Stefanie_Schmidt)\
**Post date:** [October 11, 2014, 4:20pm UTC](https://community.cesium.com/t/synchronizing-billboard-with-entity-position/1577/1 "2014-10-11T16:20:32Z")

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Hello,

I have managed to synchronize a billboard with the current position of an entity of a datasource, which is a czml file. However, when zoomed in the billboard jitters. Although, the synchronization occurs every frame.  
Here’s an example snippet how I did this:

viewer.scene.postRender.addEventListener(function () {  
if (typeof viewer.trackedEntity === ‘object’) {  
billboard.position = viewer.trackedEntity.position.getValue(viewer.clock.currentTime);  
}  
});

``

Is there a way to draw the synchronized billboard more smoothly, without putting it into the datasource’s entity?

Best regards,

Stefanie

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<div class="post-metadata">

**Author:** ![Matt\_Amato](https://sea2.discourse-cdn.com/cesium/user_avatar/community.cesium.com/matt_amato/32/1993_2.png) [@Matt\_Amato](https://community.cesium.com/u/Matt_Amato)\
**Post date:** [October 14, 2014, 8:11pm UTC](https://community.cesium.com/t/synchronizing-billboard-with-entity-position/1577/2 "2014-10-14T20:11:32Z")

</div>

Try listening to preRender instead of post render. Also, both pre/post render events pass in two parameters, scene and time. change your callback function signature to take them and use the time past in instead of viewer.clock.currentTime.

Is there a reason you are trying to manually map a billboard primitive to an entity.position instead of simple assigning a BillboardGraphics instance to the entity?